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Abstract:

A control valve assembly is provided for a load carrying vehicle that
includes a storage space and a dumping mechanism. The control valve
assembly includes a housing and a sliding valve positioned within the
housing and movable between a first position, and a second position. The
sliding valve includes a first piston that defines a first piston first
surface and a first piston second surface, and a second piston that
defines a second piston first surface and a second piston second surface.
The first piston second surface faces the second piston first surface. A
pilot system includes a first pilot passage in fluid communication with
the first piston second surface to selectively actuate the sliding valve
toward the first position, and a second pilot passage in fluid
communication with the second piston first surface to selectively actuate
the sliding valve toward the second position.

Claims:

1. A control valve assembly for a load carrying vehicle that includes a
storage space and a dumping mechanism movable between an open position
that allows access to the storage space and a closed position that
inhibits access to the storage space, the control valve assembly
comprising: a housing; a sliding valve positioned within the housing and
movable between a first position, wherein the dumping mechanism is moved
toward the open position, and a second position, wherein the dumping
mechanism is moved toward the closed position, the sliding valve
including: a first piston coupled to a first end of the sliding valve and
defining a first piston first surface and a first piston second surface,
and a second piston coupled to a second end of the sliding valve opposite
the first end and defining a second piston first surface and a second
piston second surface, the first piston second surface facing the second
piston first surface, and a pilot system including: a first pilot passage
in fluid communication with the first piston second surface to
selectively actuate the sliding valve toward the first position, and a
second pilot passage in fluid communication with the second piston first
surface to selectively actuate the sliding valve toward the second
position.

2. The control valve assembly of claim 1, further comprising a solenoid
system in communication with the sliding valve and operable in response
to an electrical signal to actuate the sliding valve between the first
position and the second position.

3. The control valve assembly of claim 2, wherein the electrical signal
includes a first electrical signal and a second electrical signal, and
the solenoid system includes a first solenoid and a second solenoid; and
wherein the first electrical signal controls the first solenoid such that
the sliding valve is actuated to the second position, and the second
electrical signal controls the second solenoid such that the sliding
valve is actuated to the first position.

4. The control valve assembly of claim 3, wherein the first solenoid is
in fluid communication with the first piston first surface to selectively
actuate the sliding valve toward the second position, and wherein the
second solenoid is in fluid communication with the second piston second
surface to selectively actuate the sliding valve toward the first
position.

5. The control valve assembly of claim 2, wherein the solenoid system is
not in fluid communication with the pilot system.

6. The control valve assembly of claim 1, wherein the housing includes a
manifold block and at least a portion of the pilot system is formed in
the manifold.

7. The control valve assembly of claim 1, wherein the first piston first
surface and the first piston second surface are fluidly isolated from
one-another, and wherein the second piston first surface and the second
piston second surface are fluidly isolated from one-another.

8. The control valve assembly of claim 1, wherein the pilot system
provides high pressured air to the sliding valve to selectively actuate
the sliding valve.

9. The control valve assembly of claim 1, wherein the piloting system is
a cross-piloting system.

10. The control valve assembly of claim 1, further comprising a lever
directly connected to a movable member of the sliding valve and movable
between a first lever position, wherein the sliding valve is moved to the
first position, and a second lever position, wherein the sliding valve is
moved to the second position.

11. The control valve assembly of claim 1, further comprising a knob
directly connected to a movable member of the valve and movable between a
first knob position, wherein the valve is moved to the first position,
and a second knob position, wherein the valve is moved to the second
position.

12. The control valve assembly of claim 11, wherein the knob includes an
indication surface extending about a substantial portion of a periphery
of the knob.

13. The control valve assembly of claim 1, further comprising a detent
that inhibits movement of the sliding valve between the first position
and the second position.

14. A control valve assembly for a load carrying vehicle that includes a
storage space and a dumping mechanism movable between an open position
that allows access to the storage space and a closed position that
inhibits access to the storage space, the control valve assembly
comprising: a housing; a sliding valve positioned within the housing and
movable between a first position, wherein the dumping mechanism is moved
toward the open position, and a second position, wherein the dumping
mechanism is moved toward the closed position, the sliding valve
including: a first piston coupled to a first end of the sliding valve,
and a second piston coupled to a second end of the sliding valve opposite
the first end; a pilot system including: a first pilot passage in fluid
communication with the first piston to selectively actuate the sliding
valve toward the first position, and a second pilot passage in fluid
communication with the second piston to selectively actuate the sliding
valve toward the second position; and a solenoid system including: a
first solenoid in fluid communication with the first piston to
selectively actuate the sliding valve toward the second position, and a
second solenoid in fluid communication with the second piston to
selectively actuate the sliding valve toward the first position, wherein
the pilot system and the solenoid system are fluidly isolated from one
another.

15. The control valve assembly of claim 14, wherein the first piston
defines a first piston first surface and a first piston second surface,
wherein the second piston defines a second piston first surface and a
second piston second surface, the first piston second surface facing the
second piston first surface, wherein the first pilot passage is in fluid
communication with the first piston second surface to selectively actuate
the sliding valve toward the first position, and wherein the second pilot
passage is in fluid communication with the second piston first surface to
selectively actuate the sliding valve toward the second position.

16. The control valve assembly of claim 15, wherein the first solenoid is
in fluid communication with the first piston first surface to selectively
actuate the sliding valve toward the second position, and wherein the
second solenoid is in fluid communication with the second piston second
surface to selectively actuate the sliding valve toward the first
position.

17. The control valve assembly of claim 14, further comprising a lever
directly connected to a movable member of the sliding valve and movable
between a first lever position, wherein the sliding valve is moved to the
first position, and a second lever position, wherein the sliding valve is
moved to the second position.

18. The control valve assembly of claim 14, further comprising a knob
directly connected to a movable member of the valve and movable between a
first knob position, wherein the valve is moved to the first position,
and a second knob position, wherein the valve is moved to the second
position.

19. The control valve assembly of claim 18, wherein the knob includes an
indication surface extending about a substantial portion of a periphery
of the knob.

20. The control valve assembly of claim 14, further comprising a detent
that inhibits movement of the sliding valve between the first position
and the second position.

Description:

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.
12/327,291, filed on Dec. 3, 2008, the contents of which are incorporated
herein by reference in their entirety.

BACKGROUND

[0002] The present invention relates to control valves used in railcars or
other load carrying vehicles. Specifically, the invention relates to
control valves that control the opening and closing of a hopper gate on
the underside of a railcar or other load carrying vehicles.

[0003] Control valves are typically used within hydraulic or pneumatic
systems to direct flow to actuators and to generally control the flow
path of a control fluid to insure proper operation of the system. Such
control valves may be used with a pneumatic system such as those used
with coal carrying railcars. Briefly, coal carrying railcars include a
hopper gate on the underside of the railcar that opens and closes to dump
coal from the railcar when over a dump site. The hopper gate is opened
and closed by a pneumatic cylinder that is controlled by the control
valve. As the railcar approaches the dump site, an air system is
pressurized to prepare for dumping. When the railcar arrives at the dump
site, the control valve provides pressurized air to the cap side of a
piston such that the piston pushes the hopper gate open to dump the coal.
After the coal has been dumped, the control valve is actuated to the
closed position and the piston is refracted such that the hopper gate is
closed and locked.

SUMMARY

[0004] In one embodiment, the invention provides a control valve assembly
for a load carrying vehicle that includes a storage space and a dumping
mechanism movable between an open position that allows access to the
storage space and a closed position that inhibits access to the storage
space. The control valve assembly includes a housing and a sliding valve
positioned within the housing and movable between a first position,
wherein the dumping mechanism is moved toward the open position, and a
second position, wherein the dumping mechanism is moved toward the closed
position. The sliding valve includes a first piston that is coupled to a
first end of the sliding valve. The first piston defines a first piston
first surface and a first piston second surface. A second piston is
coupled to a second end of the sliding valve opposite the first end and
defines a second piston first surface and a second piston second surface.
The first piston second surface faces the second piston first surface.
The control valve assembly further includes a pilot system that includes
a first pilot passage in fluid communication with the first piston second
surface to selectively actuate the sliding valve toward the first
position, and a second pilot passage in fluid communication with the
second piston first surface to selectively actuate the sliding valve
toward the second position.

[0005] In another embodiment, the invention provides a control valve
assembly for a load carrying vehicle that includes a storage space and a
dumping mechanism movable between an open position that allows access to
the storage space and a closed position that inhibits access to the
storage space. The control valve assembly includes a housing and a
sliding valve positioned within the housing and movable between a first
position, wherein the dumping mechanism is moved toward the open
position, and a second position, wherein the dumping mechanism is moved
toward the closed position. The sliding valve includes a first piston
coupled to a first end of the sliding valve, and a second piston coupled
to a second end of the sliding valve opposite the first end. A pilot
system includes a first pilot passage in fluid communication with the
first piston to selectively actuate the sliding valve toward the first
position, and a second pilot passage in fluid communication with the
second piston to selectively actuate the sliding valve toward the second
position. A solenoid system includes a first solenoid in fluid
communication with the first piston to selectively actuate the sliding
valve toward the second position, and a second solenoid in fluid
communication with the second piston to selectively actuate the sliding
valve toward the first position. The pilot system and the solenoid system
are fluidly isolated from one another.

[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a schematic of a vehicle at a dump site.

[0008]FIG. 2 is a schematic diagram of the pneumatic system of the
vehicle of FIG. 1 embodying the invention.

[0009]FIG. 3 is a perspective view of a control valve assembly embodying
the system shown in FIG. 2.

[0010] FIG. 4 is another perspective view of the control valve assembly of
FIG. 3.

[0011]FIG. 5 is a section view of the control valve assembly taken along
line 5-5 in FIG. 3 showing the control valve assembly in a first
position.

[0012]FIG. 6 is a section view of the control valve assembly taken along
line 6-6 in FIG. 4 showing the control valve assembly in a second
position.

[0013]FIG. 7 is a partial view of the control valve assembly of FIG. 3
showing the pneumatic flow paths.

[0014] FIG. 8 is a perspective view of another embodiment of a control
valve assembly embodying the invention.

DETAILED DESCRIPTION

[0015] Before any embodiments of the invention are explained in detail, it
is to be understood that the invention is not limited in its application
to the details of construction and the arrangement of components set
forth in the following description or illustrated in the following
drawings. The invention is capable of other embodiments and of being
practiced or of being carried out in various ways. Also, it is to be
understood that the phraseology and terminology used herein is for the
purpose of description and should not be regarded as limiting. The use of
"including," "comprising," or "having" and variations thereof herein is
meant to encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise, the
terms "mounted," "connected," "supported," and "coupled" and variations
thereof are used broadly and encompass both direct and indirect
mountings, connections, supports, and couplings. Further, "connected" and
"coupled" are not restricted to physical or mechanical connections or
couplings.

[0016] FIG. 1 shows a load carrying vehicle in the form of a railcar 10.
The railcar 10 includes a storage space 11 on the interior of the railcar
10 and a dumping mechanism 12 at the bottom of the storage space 11. The
dumping mechanism 12 includes a hopper gate or doors that open and close
to selectively provide access to the storage space 11. In the illustrated
embodiment, the railcar 10 rides along a rail 14 and is pictured at a
dump site 18. The dump site 18 includes a first actuator in the form of
an "open" hot rail 22 and a second actuator in the form of a "close" hot
rail 26. The illustrated railcar 10 carries a product in the form of coal
30 within the storage space 11 and dumps the coal 30 via the dumping
mechanism 12 into the dump site 18. In other embodiments, the load
carrying vehicle may be different (e.g., a truck) and may carry a
different product (e.g., aggregate), as desired. In another embodiment,
the first actuator and second actuator may be configured differently. For
example, the hot rails 22, 26 may be removed and a different actuation
system may be used, as desired.

[0017] Referring to FIG. 2, the railcar 10 includes a working fluid tank
in the form of a compressed air tank 34 that is filled by an air
compressor 38 situated elsewhere on the train or at the dump site 18. The
air flows from the compressed air tank 34, through a filter 42 to a
control valve assembly 46. The control valve assembly 46 selectively
routes air to an actuator 50 to open and close the dumping mechanism 12.

[0018] The illustrated actuator 50 is a pneumatic cylinder 54 and piston
58 arrangement. The piston 58 has a cap side 62 and a head side 66. When
high pressure air is applied to the cap side 62, the piston 58 is
extended from the cylinder 54 (to the left in FIG. 2) such that the
dumping mechanism 12 is opened. In one embodiment, the high pressure air
must drive the piston 58 past a first detent and a second detent (not
shown) to open the dumping mechanism 12. When high pressure air is
applied to the head side 66, the piston 58 is retracted into the cylinder
54 (to the right in FIG. 2) such that the dumping mechanism 12 is closed.
In other embodiments, a different working fluid may be used (e.g.,
hydraulic fluid) and the first and/or second detents may be removed, as
desired.

[0019] The control valve assembly 46 has a supply line 70 that is in
communication with the compressed air tank 34 such that the supply line
70 is supplied with high pressure air. The control valve assembly 46 also
includes an open line 74 that is in communication with the cap side 62 of
the piston 58, a close line 78 that is in communication with the head
side 66 of the piston 58, an open exhaust 82 in communication with
atmospheric pressure, and a close exhaust 86 in communication with
atmospheric pressure.

[0020] The illustrated control valve assembly 46 is a two position, five
port valve that selectively routes high pressure air from the supply line
70 to either the open line 74 or the close line 78, and selectively vents
air from either the cap side 62 of the piston 58 via the open line 74
through the open exhaust 82, or the head side 66 of the piston 58 via the
close line 78 through the close exhaust 86. In other embodiments, the
open exhaust 82 and close exhaust 86 may be combined into a common
exhaust. In such an embodiment, a two position, four port valve
configuration could be used.

[0021] The control valve assembly 46 includes a valve in the form of a
sliding spool valve having a movable spool 90 (FIGS. 5 and 6) that is
movable between a close position (as shown in FIG. 2) wherein air from
the supply line 70 is provided through the close line 78 to the head side
66 of the piston 58 to move the piston 58 toward the closed position, and
an open position (the left half of the spool 90 shown in FIG. 2) wherein
air from the supply line 70 is provided through the open line 74 to the
cap side 62 of the piston 58 to move the piston 58 toward the open
position. When the spool 90 is in the close position, air from the cap
side 62 of the piston 58 is vented through the open line 74 and out the
open exhaust 82. When the spool 90 is in the close position, air from the
head side 66 of the piston 58 is vented through the close line 78 to the
close exhaust 86. The close exhaust 86 is blocked when the spool 90 is in
the close position and the open exhaust 82 is blocked when the spool 90
valve is in the open position. In other embodiments, other types of
valves having a different movable member that switches the valve between
two or more positions can also be substituted.

[0022] The control valve assembly 46 includes a first actuation system in
the form of an "open" solenoid 94 and a "close" solenoid 98. The
illustrated open solenoid 94 is in electrical communication with an open
hot shoe/touch pad 99 on the railcar 10 that selectively contacts the
open hot rail 22. When the open hot shoe/touch pad 99 contacts the open
hot rail 22, an electric signal is provided to the open solenoid 94 such
that the open solenoid 94 moves the spool 90 to the open position. The
illustrated close solenoid 98 is in electrical communication with a close
hot shoe/touch pad 100 on the railcar 10 that selectively contacts the
close hot rail 26. When the close hot shoe/touch pad 100 contacts the
close hot rail 26, an electric signal is provided to the close solenoid
98 such that the close solenoid 98 moves the spool 90 to the close
position. In another embodiment, the hot shoe/touch pads 99, 100 may be,
for example, simply a disc, washer, or plate that is mounted on the side
of the railcar 10. Additionally, the electrical signals may be sent to
the hot shoes/touch pads 99, 100 from another source (e.g., a hand held
battery, another DC source, or an AC source). In the case of the supply
voltage being an AC signal, the hot shoe/touch pad 99, 100 may include a
transformer or another voltage manipulation device. In another
embodiment, the open hot shoe/touch pad 99 and the close hot shoe/touch
pad 100 can be a single hot shoe (not shown), such that when the single
hot shoe contacts the open hot rail 22 the control valve assembly 46 is
moved to the open position, and when the single hot shoe contacts the
close hot rail 26 the control valve assembly 46 is moved to the close
position. In such an embodiment, the open hot rail 99 and close hot rail
100 typically have opposite polarity (i.e., positive and negative).

[0023] The control valve assembly 46 also includes a second actuation
system in the form of a lever 102 that is coupled to the spool 90. The
lever 102 is manipulated by a user between a first lever position and a
second lever position. In the illustrated embodiment, the first lever
position is a released position, wherein the spool 90 is moved to the
open position, and the second lever position is an applied position,
wherein the spool 90 is moved to the close position (as shown in FIG. 2).
Alternatively, the first lever position could be the applied position and
the second lever position could be the released position.

[0024] The control valve assembly 46 also includes a third actuation
system in the form of a knob 106 that is coupled to the spool 90. The
knob 106 is manipulated by the user between a first knob position and a
second knob position. In the illustrated embodiment, the first knob
position is an extended position, wherein the spool 90 is moved to the
open position, and the second knob position is a retracted position,
wherein the spool 90 is moved to the close position (as shown in FIG. 2).
Alternatively, the first knob position could be the retracted position
and the second knob position could be the extended position.

[0025] The control valve assembly 46 also includes a fourth actuation
system in the form of a open pilot passage 110 and a close pilot passage
114. The open pilot passage 110 moves the spool 90 to the open position
and the close pilot passage 114 moves the spool 90 to the close position.
The open and close pilot passages 110, 114 are in communication with a
remote actuator (not shown) such that high pressure air is selectively
supplied by the remote actuator to move the spool 90 to either the open
position or the close position. In the illustrated embodiment, the remote
actuator is a remote pneumatic switch that may be manually switched
between an open and close position by the user. Other known actuation
systems can also be substituted or added.

[0026] The detailed structure of the control valve assembly 46 will be
discussed with respect to FIGS. 3-7. With specific reference to FIGS. 3
and 4, the control valve assembly 46 includes a manifold block 118, a
lever housing 122, a knob housing 126, and a valve housing 130. The
manifold block 118 has a supply port 134 that communicates with the
supply line 70, an open port 138 that communicates with the open line 74,
a close port 142 that communicates with the close line 78, an open
exhaust port 146 that communicates with the open exhaust 82, and a close
exhaust port 150 that communicates with the close exhaust 86. Portions of
the supply line 70, open line 74, close line 78, open exhaust 82, and
close exhaust 86 are formed in the manifold block 118 (see FIG. 5). The
manifold block 118 also includes an open pilot port 154 and a close pilot
port 158 that are in communication with the open pilot passage 110 and
close pilot passage 114, respectively. Additionally, portions of the open
pilot passage 110 and the close pilot passage 114 are formed in the
manifold block 118.

[0027] The lever housing 122 is coupled to a sealing member 123 that is
sealingly attached to the valve housing 130. The lever 102 includes a
shaft 162 that is coupled to the lever housing 122 by a pivot rod 166,
and a lever yoke 170 is threaded or otherwise secured onto the shaft 162.
In the illustrated embodiment, the lever yoke 170 is attached to a
linkage (not shown, e.g., a sheathed transmission cable) that may be
manipulated by the user from a remote location, such as the opposite side
of the railcar 10. In other embodiments, the lever 102 may be manipulated
directly.

[0028] The knob housing 126 is sealingly attached to the valve housing
130. The knob 106 has a indication surface 174 around the periphery and
is at least partially surrounded by a shroud 178 that is attached to the
knob housing 126. The shroud 178 obscures the indication surface 174 and
the knob 106 is disposed substantially entirely within the shroud 178
when the knob 106 is in the retracted position (FIG. 3), and the knob 106
at least partially extends outside the shroud 178 such that the
indication surface 174 is visible outside the shroud 178 when the knob
106 is in the extended position (FIG. 4). In the illustrated embodiment,
the end of the knob 106 is always visible. However, the sides of the knob
106 where the indication surface 174 is disposed may be hidden by the
shroud 178 (e.g., when the knob is in the retracted position, FIG. 3). In
another embodiment shown in FIG. 8, the shroud 178 may extend around
substantially 360 degrees such that a user may not access the back side
of the knob 106 with his/her hand to move the valve 46 from the closed
position to the open position. In the embodiment shown in FIG. 8, a tool
(not shown) is inserted into a tool access aperture 180 to shift the knob
106 from the retracted position to the extended position. The tool access
aperture 180 is shown on a side of the shroud 178, however, could be
located in other positions on the shroud 178 (e.g., bottom dead center).
In yet another embodiment, an additional cover (not shown) may cover
and/or selectively enclose the control valve assembly 46 or the shroud
178 to provide additional protection from the elements or outside
vandalism (e.g., snow, ice, dirt, vandals, accidental contact).

[0029] The open and close solenoids 94, 98 are attached to the valve
housing 130 and portions of the open and close solenoids 94, 98 are
disposed within the valve housing 130. Additionally, a wiring conduit 182
is connected to the open and close solenoids 94, 98 and houses power
lines 186 that couple the open solenoid 94 to the open hot shoe/touch pad
99 and the close solenoid 98 to the close hot shoe/touch pad 100.

[0030] Referring to FIGS. 5 and 6, the valve housing 130 includes a spool
bore 190 that is shaped to receive the spool 90. Two seals 194 are
positioned near the center of the spool 90 to create a sealing
relationship between the spool 90 and the spool bore 190. The supply line
70, open line 74, open exhaust 82, close line 78, and close exhaust 86
communicate from the respective ports 134, 142, 146, 150, 154, 158 to the
spool bore 190. Two seals 194 flank the close exhaust 86 to block
communication with the spool bore 190 while the spool 90 is in the close
position (FIG. 5), and likewise, two seals 194 flank the open exhaust 82
to block communication with the spool bore 190 when the spool 90 is in
the open position (FIG. 6). The two outermost seals 194 in the spool bore
190 also inhibit high pressure air from escaping the valve housing 130.

[0031] The knob 106 includes a knob spindle 198 that extends through the
knob housing 126 and directly threads into the spool 90. The knob housing
126 has a seal 194 that contacts the knob spindle 198 to inhibit
contaminants from accessing the spool 90 or other valve components from
the exterior of the control valve assembly 46. Two detent recesses 202
are formed in the knob housing 126 and a spring detent 206 is positioned
on the knob spindle 198. The spring detent 206 selectively engages the
detent recesses 202 and inhibits movement of the knob 106. The knob
spindle 198 is directly connected to the spool 90, therefore the spring
detent 206 inhibits the movement of the spool 90. To move the spool 90, a
sufficient force must be applied to overcome the spring detent 206.

[0032] The lever 102 includes a lever spindle 210 that extends through the
lever housing 122 and directly threads into the spool 90. The lever
housing 122 has a seal 194 that contacts the lever spindle 210 to inhibit
contaminants from accessing the spool 90 or other valve components from
the exterior of the control valve assembly 46. The lever spindle 210 is
connected to the shaft 162 by a pin and cradle arrangement 214 such that
movement of the lever 102 between the applied position (FIG. 5) and the
released position (FIG. 6) moves the lever spindle 210 and spool 90
between the close position (FIG. 5) and open position (FIG. 6),
respectively.

[0033] The open pilot passage 110 communicates with a first chamber 218
that is formed in the valve housing 130. The knob housing 126 forms one
wall of the first chamber 218. A first piston 222 is disposed within the
first chamber 218 and positioned on the knob spindle 198. The first
piston 222 is held rigidly in place relative to the knob spindle 198 and
the spool 90 via shoulders formed in the knob spindle 198 and the spool
90. Seals 194 on the inner and outer diameters of the first piston 222
inhibit leakage of pressurized air from one side of the piston 222 to the
other.

[0034] The close pilot passage 114 communicates with a second chamber 226
that is formed in the valve housing 130. The lever housing 122 forms one
wall of the second chamber 226. A second piston 230 is disposed within
the second chamber 226 and positioned on the lever spindle 210. The
second piston 230 is held rigidly in place relative to the lever spindle
210 and the spool 90 via shoulders formed in the lever spindle 210 and
the spool 90. Seals 194 on the inner and outer diameters of the second
piston 230 inhibit leakage of pressurized air from one side of the piston
230 to the other.

[0035] In another embodiment, the second piston 230 is removed such that
pressurized air acts only on the spool 90 itself to shift the valve 46
from the closed position to the open position. This may be desirable when
a larger pressure is desired to move the valve 46 to the open position
than to move the valve 46 to the closed position. The smaller surface
area presented by the spool 90 (as opposed to the larger surface area
presented by the piston 230) requires more air pressure to move the spool
90. In one example, an air pressure of 40 psi is required to move the
valve 46 to the open position, and 10-15 psi is required to move the
valve 46 to the closed position. In other embodiments, different
pressures and different pressure differentials may be used, as desired.

[0036] Referring to FIG. 7, the supply line 70 is in communication with an
open solenoid supply line 234 via a T-shaped gasket 238 positioned
between the manifold block 118 and the valve housing 130. The open
solenoid supply line 234 provides high pressure air to the open solenoid
94.

[0037] The open solenoid 94 includes a open valve seat 242 and an open
plunger 246 that is movable between a supply position (FIG. 6) and a null
position (FIG. 5). The open plunger 246 is lifted from the open valve
seat 242 while in the supply position. The open plunger 246 is biased
toward the null position by a spring 250 and moves to the supply position
when supplied with the electric signal. When the open plunger 246 is in
the supply position, high pressure air communicates with an open solenoid
actuation line 254 (FIG. 7) that communicates with the second chamber 226
and biases the second piston 222 such that the spool 90 is moved to the
open position (FIG. 6). When the open plunger 246 is in the null
position, substantially no communication exists between the open solenoid
supply line 234 and the open solenoid actuation line 254.

[0038] Similar to the open solenoid 94, the supply line 70 is in
communication with a close solenoid supply line 258 via the T-shaped
gasket 238 positioned between the manifold block 118 and the valve
housing 130. The close solenoid supply line 258 provides high pressure
air to the close solenoid 98. The close solenoid 98 is substantially
similar to the open solenoid 94 and includes a close valve seat 262 and a
close plunger 266 that is movable between a supply position (not shown
but similar to the supply position of the open plunger 246 shown in FIG.
6) and a null position (FIGS. 5 and 6). The close plunger 266 is biased
toward the null position by a spring 270 and moves to the supply position
when supplied with the electric signal. When the close plunger 266 is in
the supply position, high pressure air communicates with a close solenoid
actuation line 274 (FIG. 7) that communicates with the first chamber 218
and biases the first piston 222 such that the spool 90 is moved to the
close position. When the close plunger 266 is in the null position,
substantially no communication exists between the close solenoid supply
line 258 and the close solenoid actuation line 274.

[0039] FIG. 8 shows another embodiment where the lever housing 122 and
lever 102 have been removed. The invention provides a valve arrangement
with a high degree of flexibility that is able to meet a number of
different needs that may be presented by users. For example, the knob 106
and knob housing 126, the open pilot passage 110 and the close pilot
passage 114, and/or the lever 102 and lever housing 122 could be added or
removed to suit the user's requirements.

[0040] In one mode of operation, as the railcar 10 approaches the dump
site 18 (see FIG. 1) the user may first inspect the control valve
assembly 46 to identify the position of the spool 90. If the spool 90 is
in the open position, the knob 106 will be in the extended position and
the indication surface 174 will be visible (see FIG. 6). The indication
surface 174 is easily identified during the day and in the dark. The user
may use a flashlight to inspect the control valve assembly 46 such that
if the knob 106 is in the extended position the indication surface 174
will be illuminated by the flashlight. In this way, the knob 106 is a
clear visual indicator of the spool 90 position and therefore the valve
position. If the user identifies that the spool 90 is in the open
position, the spool 90 should be actuated to the close position, either
by manual manipulation of the knob 106 or the lever 102, or by use of the
pilot passages 110, 114 with pressurized air from the compressed air tank
34 or from an external source. In another embodiment, the knob 106 could
be in the extended position to indicate that the valve is in the closed
position. With this arrangement, a user would see the indication surface
174 as an indication of a closed valve. In the illustrated embodiment,
the indication surface 174 is a reflective red color and indicates that
the valve is in the open position and should be moved to the closed
position. In other embodiments, the indication surface 174 may be another
warning color (e.g., orange), non-reflective, or have other suitable
indicative characteristics, as desired.

[0041] Once the user identifies that the spool 90 is in the close position
(see FIG. 5), the air compressor 38 is turned on such that high pressure
air is provided to the compressed air tank 34 (see FIG. 2). High pressure
air then flows through the supply line 70 and into the spool bore 190.
The spool 90 is in the close position (see FIG. 5), therefore high
pressure air from the supply line 70 passes to the close line 78 to apply
high pressure air to the head side 66 of the piston 58 while air from the
cap side 62 of the piston 58 is vented through the open line 74 and out
the open exhaust 82 (see FIGS. 2 and 5). This maintains the dumping
mechanism 12 in the closed position while the railcar 10 is not
positioned within the dump site 18 such that inadvertent dumps are
inhibited.

[0042] As the railcar 10 enters the dump site 18, the open hot shoe/touch
pad 99 contacts the open hot rail 22 and the electrical signal is sent to
the open solenoid 94. The open plunger 246 then moves from the null
position to the supply position such that high pressure air is supplied
to the second piston 230 (right side of the second piston as shown in
FIGS. 5 and 6) and the spool 90 is moved to the open position (FIG. 6).

[0043] Once the spool 90 is in the open position, high pressure air from
the supply line 70 communicates through the spool bore 190 and the open
line 74 to apply high pressure air to the cap side 62 of the piston 58
while air from the head side 66 of the piston 58 is vented through the
close line 78 and out the close exhaust 86 (see FIG. 6). This biases the
actuator 50 toward the open position such that the coal 30 is dumped from
the railcar 10 into the dump site 18.

[0044] After the open hot shoe/touch pad 99 breaks contact with the open
hot rail 22, the solenoid spring 250 returns the open plunger 246 to the
null position such that high pressure air is not provided to the second
piston 230. The dumping mechanism 12 is then maintained in the open
position for a predetermined length of time to ensure the load of coal 30
is fully dumped from the railcar 10.

[0045] As the railcar 10 continues to move through the dump site 18, the
close hot shoe/touch pad 100 contacts the close hot rail 26 and the
electrical signal is sent to the close solenoid 98. The close plunger 266
then moves from the null position to the supply position such that high
pressure air is supplied to the first piston 222 (left side of the first
piston as shown in FIGS. 5 and 6) and the spool 90 is moved to the close
position (FIG. 5).

[0046] Once the spool 90 is in the close position, high pressure air from
the supply line 70 communicates through the spool bore 190 and the close
line 78 to apply high pressure air to the head side 66 of the piston 58
while air from the cap side 62 of the piston 58 is vented through the
open line 74 and out the open exhaust 82 (see FIGS. 2 and 5). This biases
the actuator 50 toward the close position such that the dumping mechanism
12 is closed and access to the storage space 11 is inhibited.

[0047] After the dumping mechanism 12 is closed and the close hot
shoe/touch pad 100 breaks contact with the close hot rail 26, the
solenoid spring 270 returns the close plunger 266 to the null position
such that high pressure air is not provided to the first piston 222. The
spool 90 remains in the close position such that any air remaining within
the compressed air tank 34 is provided to the head side 66 of the
actuator 50 to maintain the dumping mechanism 12 in the closed position.

[0048] The above described operation is an automated dumping procedure. In
other embodiments, the electrical signal is sent to the hot shoes/touch
pads 99, 100 manually. For example, the operator at the dump site may
simply use a series of batteries connected in series that equal 24 VDC
and touches the positive terminal to the desired hot shoe/touch pad 99,
100 and the negative terminal to the railcar 10 and the corresponding
solenoid 94, 98 is energized. Other energy sources may also be used to
energize the solenoids 94, 98, as desired.

[0049] In another mode of operation, the spool 90 may be moved between the
open position and the close position manually by the knob 106 without the
presence of pressurized air from the railcar 10 or any other source. The
user may manually manipulate the knob 106 to shift the spool 90 between
the open position and the close position. The spring detent 206 inhibits
the movement of the spool 90 such that inadvertent shifting is inhibited.

[0050] In another mode of operation, the spool 90 may be moved between the
open position and the close position manually by the lever 102 without
the presence of pressurized air from the railcar 10 or any other source.
The user may manually manipulate the lever 102 to shift the spool 90
between the open position and the close position. A linkage (not shown)
may be arranged such that the user can manipulate the lever 102 from the
opposite side of the railcar 10.

[0051] In another mode of operation, the spool 90 may be shifted between
the open position and the close position by the open pilot passage 110
and the close pilot passage 114, respectively. Pressurized air may be
supplied to the pilot passages 110, 114 by the air compressor 38 or by a
different air source on or off of the railcar 10. For example, the dump
site 18 may have an air compressor (not shown) that the user may connect
to the open pilot passage 110 or the close pilot passage 114 to actuate
the control valve assembly 46.

[0052] Conventional pilots operate by applying high pressure air to the
outside of a valve to push the valve to the desired position. For
example, in FIG. 5 a conventional pilot would apply pressure on the right
side of the second piston 230 to shift the spool 90 to the open position.
The invention provides a cross-piloting feature wherein the open pilot
passage 110 provides high pressure air to the right side of the first
piston 222 to move the spool 90 to the open position. In this way the
open pilot passage 110 and the close solenoid 98 are not in communication
and the control valve assembly 46 operates significantly better. Likewise
to move the spool 90 to the close position, high pressure air is provided
through the close pilot passage 114 to the left side of the second piston
230 and the spool 90 is shifted to the close position. Maintaining pilot
lines and solenoid lines separate allows a user to utilize pilot features
without connecting directly to the solenoid system. This design is more
elegant than previous attempts and provides an improved piloting system.

[0053] The invention provides multiple actuation systems that are
interconnected such that movement of one, causes movement of the others.
For example, movement of the knob 106 moves the spool 90 and also the
lever 102. In this way, movement of any one of the knob 106, the spool
90, and/or the lever 102 causes movement of the others of the knob 106,
the spool 90, and the lever 102, and the position of the valve is
indicated by the knob 106 and the lever 102.

[0054] The knob 106, the spool 90, and the lever 102 are directly
connected. With respect to this application, direct connection means any
mechanical connection, including linkages, such that movement of a first
component directly causes the movement of a second component and movement
of the second component directly causes the movement of the first
component (e.g., the spool 90, the knob 106, and the lever 102).

[0055] Various features and advantages of the invention are set forth in
the following claims.